Master cylinder

Abstract

A master cylinder including a cylinder body having a tubular shape with a closed end; and a piston having one side slidably inserted into the cylinder body and another side that projects from the cylinder body. The piston and the cylinder body define a pressure chamber for generating hydraulic pressure. The master cylinder also includes a protecting member for covering the side of the piston projects from the cylinder body. The protecting member is adapted to extend and contract, and limit backward movement of the piston.

1. A master cylinder comprising:
 a cylinder body having a tubular shape with a closed end; 
 a piston having one side thereof slidably inserted into the cylinder body and another side thereof projecting from the cylinder body, the piston and the cylinder body defining a pressure chamber for generating hydraulic pressure; and 
 a protecting member for covering said another side of the piston projecting from the cylinder body, the protecting member being adapted to extend and contract, and limit backward movement of the piston, wherein; 
 the protecting member comprises a first cover member having one side thereof fixedly engaged with the cylinder body, and a second cover member having one side thereof slidably engaged with another side of the first cover member; 
 an outer circumferential surface of the one side of the second cover member is slidably engaged with an inner circumferential surface of the another side of the first cover member; and 
 the one side of the second cover member has an enlarged diameter portion which is adapted to slide on the inner circumferential surface of the first cover member. 
 
   
   
     2. A master cylinder according to  claim 1 , wherein the another side of the first cover member has a guide portion for guiding the second cover member to move in a direction parallel to an axis of the piston. 
   
   
     3. A master cylinder according to  claim 1 , wherein the protecting member limits the backward movement of the piston at the another side of the piston projecting from the cylinder body. 
   
   
     4. A master cylinder according to  claim 3 , wherein the axial extension of the second cover member is limited relative to the first cover member; and another side of the second cover member is provided with a disc that has an insertion hole at a center thereof, and the disc abuts against another end surface of the piston projecting from the cylinder body. 
   
   
     5. A master cylinder according to  claim 3 , wherein the another side of the first cover member has a guide portion for guiding the second cover member to move in a direction parallel to an axis of the piston. 
   
   
     6. A master cylinder comprising:
 a cylinder body having a tubular shape with a closed end; 
 a piston having one side slidably inserted into the cylinder body and another side projecting from the cylinder body, the piston and the cylinder body defining a pressure chamber for generating hydraulic pressure; and 
 a protecting member for covering the another side of the piston projecting from the cylinder body, the protecting member being adapted to extend and contract, and limit backward movement of the piston, 
 wherein the protecting member comprises; 
 a first cover member having one side and another side, said one side being attached to the cylinder body; 
 a second cover member having one side and another side, the second cover member and the first cover member being adapted to cover the one side of the piston projecting from the cylinder body, wherein 
 the one side of the second cover member is slidably engaged with the another side of the first cover member, wherein the protecting member is capable of extending and contracting, and 
 wherein the protecting member has a restricting member for preventing the second cover member from being removed from the first cover member and for limiting backward movement of the piston relative to the cylinder body, 
 wherein the restricting member comprises an enlarged diameter portion formed on one side of the second cover member, the enlarged diameter portion being adapted to slide on the inner circumferential surface of the first cover member. 
 
   
   
     7. A master cylinder comprising:
 a cylinder body having a tubular shape with a closed end; 
 a piston having one side thereof slidably inserted into the cylinder body and another side thereof projecting from the cylinder body, the piston and the cylinder body defining a pressure chamber for generating hydraulic pressure; and 
 a protecting member for covering the another side of the piston projecting from the cylinder body, the protecting member being adapted to extend and contract, and limit backward movement of the piston, 
 wherein an output rod of a booster is adapted to abut against the piston, such that the protecting member contracts when forward movement of the output rod exceeds a predetermined distance. 
 
   
   
     8. A master cylinder according to  claim 7 , wherein the protecting member abuts against the output rod and contracts when forward movement of the output rod exceeds a predetermined distance. 
   
   
     9. A master cylinder according to  claim 7 , wherein the protecting member comprises a first cover member having one side thereof fixedly engaged with the cylinder body, and a second cover member having one side thereof slidably engaged with another side of the first cover member, and
 when movement of the output rod exceeds a predetermined distance, the output rod and the second cover member abut against each other and move forward together such that the protecting member contracts. 
 
   
   
     10. A master cylinder according to  claim 7 , wherein the protecting member comprises a first cover member having one side thereof fixedly engaged with the cylinder body, and a second cover member having one side thereof slidably engaged with another side of the first cover member, and
 the one side of the second cover member has an enlarged diameter portion that is adapted to slide on the inner circumferential surface of the first cover member. 
 
   
   
     11. A master cylinder according to  claim 8 , wherein the protecting member comprises a first cover member having one side that is fixedly engaged with the cylinder body, and a second cover member having one side that is slidably engaged with another side of the first cover member, and
 the one side of the second cover member has an enlarged diameter portion that is adapted to slide on the inner circumferential surface of the first cover member. 
 
   
   
     12. A master cylinder according to  claim 8 , wherein the protecting member comprises a first cover member having one side that is fixedly engaged with the cylinder body, and a second cover member having one side that is slidably engaged with another side of the first cover member, and
 an outer circumferential surface on one side of the second cover member is slidably engaged with an inner circumferential surface on another side of the first cover member. 
 
   
   
     13. A master cylinder according to  claim 8 , wherein the protecting member comprises a first cover member having one side that is fixedly engaged with the cylinder body, and a second cover member having one side that is slidably engaged with another side of the first cover member, and
 an inner circumferential surface on one side of the second cover member is slidably engaged with an outer circumferential surface on another side of the first cover member. 
 
   
   
     14. A master cylinder according to  claim 10 , wherein the another side of the first cover member has a guide portion for guiding the second cover member to move in a direction parallel to an axis of the piston. 
   
   
     15. A master cylinder according to  claim 7 , wherein the protecting member limits backward movement of the piston at the another side of the piston projecting from the cylinder body. 
   
   
     16. A master cylinder according to  claim 8 , wherein the protecting member limits backward movement of the piston at the another side of the piston projecting from the cylinder body. 
   
   
     17. A master cylinder according to  claim 7 , wherein the protecting member comprises a first cover member having one side that is fixedly engaged with the cylinder body; and a second cover member having one side that is slidably engaged with another side of the first cover member, the second covering member being limited in axial extension thereof relative to the first cover member, and
 the second cover member of the protecting member abuts against another side of the piston projecting from the cylinder body so as to limit backward movement of the piston. 
 
   
   
     18. A master cylinder according to  claim 17 , wherein the protecting member comprises a disc on another side of the second cover member, the disc having an insertion hole at a center thereof, and the disc is adapted to abut against an end surface on another side of the piston projecting from the cylinder body. 
   
   
     19. A master cylinder according to  claim 15 , wherein the protecting member comprises a first cover member having one side that is fixedly engaged with the cylinder body, and a second cover member having one side that is slidably engaged with another side of the first cover member, and
 the one side of the second cover member has an enlarged diameter portion that is adapted to slide on the inner circumferential surface of the first cover member. 
 
   
   
     20. A protecting member for covering one side of a piston projecting from a cylinder body of a master cylinder, the protecting member comprising:
 a first cover member having one side and another side, said one side being attached to the cylinder body; 
 a second cover member having one side and another side, the second cover member and the first cover member being adapted to cover the one side of the piston projecting from the cylinder body, wherein 
 the one side of the second cover member is slidably engaged with the another side of the first cover member, wherein the protecting member is capable of extending and contracting, 
 wherein the protecting member has a restricting member for preventing the second cover member from being removed from the first cover member and for limiting backward movement of the piston relative to the cylinder body, and 
 wherein the restricting member comprises an enlarged diameter portion formed on one side of the second cover member, and the enlarged diameter portion is adapted to slide on the inner circumferential surface of the first cover member.